The present invention is directed to a metallic can having a microseam formed by the microseaming process of U.S. Pat. No. 5,320,468, and refers particularly to the seams formed with the ends of the can, either the tops or the bottoms, by which, due to a substantial reduction of the dimensions of the hooks and other fixing folds, a considerable and advantageous reduction of the diameters of the cut-outs of the material employed for the manufacture of the top and end of a can is obtained. In addition, a significant reduction of the height of the can body may be obtained, where desirable, and this without change of the holding capacity of the can. This is a process from which substantial savings of metal sheet results, both in quantity as well as by enabling the employment of thinner and harder sheet metal, for example, of 0.16 mm thickness and DR8 temper, in the case where tinplate (steel coated with tin) is used, the price of which is 21.2 to 28.3% lower than that of the conventionally used metal sheet, i.e. of 0.22 to 0.24 mm thickness and the normal temper required. In addition, the cans having a microseam of the present invention may be manufactured using any metal appropriate to can making, such as aluminum.
As is known to those with knowledge of the matter, the currently used conventional cans designed to serve as packing for the most diverse products, particularly for food products and the so-called sanitary cans, are normally obtained by using tinplate of 0.22 to 0.24 mm thickness with the normal temper required for the top and the end of a can, features which would also allow the employment of this metal sheet for micro-seaming, however, without the advantages of large savings of 21.2 to 28.3% obtained as a result of the use of a metal sheet of 0.16 mm thickness and DR8 temper, as outlined by the microseaming process.
The subject microseamed metallic can provides substantial savings, both by the substantial reduction of diameters of the cut-outs for the top and the end of a can, and this as a consequence of the reduction of the dimensions of the hooks and other fixing folds, as well as by the reduction of height provided to the can body without changing its holding capacity. These savings become more significant due to the employment of a thinner and harder metal sheet, for example, of 0.16 mm thickness with DR8 temper tinplate, as compared to the conventionally used metal sheet of 0.22 to 0.24 mm thickness and the normal temper required for the top and the end of a can.
This new metallic can may be made with an electrically welded (3 piece cans) or deep drawn body (2 piece cans), i.e. those bodies with no lap or two thicknesses where the joint is obtained by folds soldered with tin or lead or thermoplasts, a condition which renders this new can infeasible.
The new metallic can and its manufacturing process as stated before is represented in the attached drawings which show, for comparison purposes, both the cut-out discs of the top and end, as well as the fixed parts and the can body, with their respective dimensions, as follows: